Add build action

.forgejo/workflows/build.yaml

@@ -0,0 +1,22 @@
+on: [push]
+jobs:
+  test:
+    runs-on: container
+    steps:
+      - uses: actions/checkout@v4
+      - uses: pnpm/action-setup@v4
+        name: Install pnpm
+        with:
+          version: 9
+          run_install: false
+
+      - name: Install Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: 'pnpm'
+
+      - name: Install dependencies
+        run: pnpm install
+
+      - run: ng build